NASA-DOD PB-FREE ELECTRONICS REWORK PROJECT: EFFECT OF IX AND 2X EUTECTIC SOLDER REWORK ON VIBRATION RELIABILITY

摘要

Crane Naval Surface Warfare Center, a NASA-DOD Consortium member, added 30 test vehicles to the NASA-DOD Pb-free Electronics study (Project 2) in support of their Naval Supply Command (NAVSUP) sponsored "Logistics Impact of Pb-free Circuits/Components" project to quantify the effects of rework of Pb-free solder joints with SnPb solder. Multipass SnPb IX and 2X rework was performed on Pb-free DIP, TQFP-144, TSOP-50, LCC and QFN components on SAC3O5 (24 boards) and SN100C (6 boards) soldered assemblies. Nine (9) boards were tested in drop shock, nine (9) in vibration, and eight (8) in accelerated thermal cycling test. The boards were vibration tested for one hour each at 8, 10, 12, 14, 16, 18, 20, and 28 Grms. An event detector was used to electrically monitor and record failures. Overall, there were 461 failures out of a total of 567 components. The results appear to have a significant amount of variation. Our preliminary conclusion of this study is that, for the components reworked in this study, a qualified rework facility with a capable process can rework Pb-free boards with SnPb solder alloy and create solder joints that have reliability comparable to as-manufactured Pb-free assemblies.